The present invention relates in general to connectors for medical fluid lines, and more specifically regards a male luer lock connector of the type comprising an elongated tubular body having a portion with a cylindrical external surface and an end portion with an external luer cone, and a bushing having an internal thread in which a female luer lock connector can be screwed, the end portion with external luer lock of the tubular body of the male luer lock connector being designed to engage axially with the female luer lock connector.